Try some tea! Camellia sinensis

Mine is a little over a year and a half old, and it just flowered for the first time! I have made 1 (one) cup of tea from it so far (:

I'm planning to do a sump pump depth gauge too at some point as an emergency "pump is busted!" alarm - very interested if you don't mind sharing your thoughts for that design.

The measurement of percent humidity is dependent on temperature - cold air can hold less moisture. For the same moisture content, the lower temperature will have a higher percentage of its capacity. If you want a measure that is independent of temperature, look into something like Dew Point.